Racking means for circular knitting machines



Nov. 23, 1965 F. E. DEANS ETAL 3,213,830

BACKING MEANS FOR CIRCULAR KNITTING MACHINES Filed Sept. 15, 1964 3 Sheets-Sheet 1 FlG.3.

Nov. 23, 1965 F. E. DEANS ETAL 3,218,830

BACKING MEANS FOR CIRCULAR KNITTING MACHINES 95 f :%2 15% 5 ii 23 -22 22 in ii A 1 3 5 2o 2(5 20 F1e.2c. s 'FIG.2D.

F G 2 l-vslvmesl Nov. 23, 1965 F. E. DEANS ETAL 3,218,830

BACKING MEANS FOR CIRCULAR KNITTING MACHINES Filed Sept. 15, 1964 3 Sheets-Sheet 3 I/vysr/raes United States Patent 3,218,830 RACKING MEANS FOR CIRCULAR KNITTING MACHINES Frederick Edward Deans and John Michael Klee,

Leicester, England, assignors to The Bentley Engineering Company Limited Filed Sept. 15, 1964, Ser. No. 396,593 Claims priority, application Great Britain, Sept. 20, 1963, 37,105/ 63 19 Claims. (Cl. 66154) This invention is for improvements in or relating to racking means for knitting machines and is concerned more particularly with racking means used in circular knitting machines for effecting racking movements of machine controlling devices at appropriate times during the performance of knitting operations. The invention has for an object to provide means whereby the racking of a control means may be effected selectively in such manner as to provide for a particularly large number of alternative control movements.

The various functions performed by instrumentalities in circular knitting machines are usually controlled by cams attached to a cylinder or control drum. Racking movements are imparted to the control drum at appropriate times during the performance of a knitting operation in order to advance the cams against or away from followers employed to transmit movement to the various parts of the machine, for the operation of such instrumentalities as movable needle cams, mechanisms controlling yarn changes and other functions well understood by those familiar with knitting machines. The racking movements of the drum are usually effected under the cotnrol of a pattern or control chain which is racked round at regular intervals through a complete circuit during the knitting of a complete article, the times at which the control drum is racked being determined by the positions of projections in the form of studs on the chain. There are a number of ways of controlling the racking of the drum according to a pre-arranged pattern but these are mostly restricted to certain pattern arrangements which cannot easily be changed. A major disadvantage of known methods of drum racking con trol is that, with the increasing complexity of modern machines it has become more and more difficult to obtain suflicient moves of the drum and sufficient variation in timing of the moves to cope with the wide range of patterns and styles expected in present day knitwear. The invention accordingly seeks to provide a form of racking mechanism for operating on a control drum suitable for various types of circular knitting machines and capable of having its pattern or racking sequence changed at will in a simple manner. The invention also seeks to provide means allowing a control drum to be racked more frequently in a knitting cycle and with greater choice of timing with respect to the knitting cycle than has been possible previously.

According to this invention there is provided racking mechanism comprising a driven rack member, pawl means to engage the rack member, control means (e.g. a control chain) for activating said pawl means to engage and operate the rack member when required, pawl driving means to move the pawl means through a plurality of operating strokes during each period of activation by the control means, and rack selecting means operative to cause the pawl means to operate the rack member only at a predetermined operative stroke or strokes of the pawl means. Thus the racking mechanism pro vides a possibility of operating the rack member in a plurality of alternative ways selectively whereby a range of different racking movements is permitted giving rise to additional patterning possibilities. With a control ice drum as aforementioned coupled to the driven rack member an additional range of racking movements of the drum is provided enabling it to cope with a wider range of patterning possibilities than would otherwise be possible. The pawl means may be caused to operate the rack member only at a predetermined stroke or strokes by being bluflFed so as to be ineffective at its remaining stroke or strokes during a period of activation.

In a convenient construction the driven rack member is in the form of a rack wheel which is directly coupled to the control drum of the machine. The pawl means co-operating with the rack wheel may comprise a plurality of pawls operating seriatim to produce a plurality of sequential racking movements any or all of which can be selected by means of the rack selecting means to be effective in advancing the rack wheel. Thus in one convenient arrangement there may be two pawls arranged side by side to co-operate with the rack member, and they may be advanced alternately one being retracted whilst the other is advanced and each being caused to perform a plurality of operative stroke-s at each activation of the pawl means. Thus at each such activation there is a potential of at least four steps of racking movement which can be applied to the rack member, preferably arranged to be in continuous succession without intervening pauses, and by means of the rack selecting means any one of such steps of movement can be selected to occur alone or together with another one or more of such steps. Thereby diflerent extents of racking movements can be selected to occur at different activations of the pawl means and shorter than normal racking movements can be timed differently to suit requirements.

Conveniently a pawl arrangement as just described may be brought into action by a stud or projection on a control chain forming the control means aforesaid by having the pawls normally bluffed so as to be racked idly and released from the blufiing means by the action of the stud or projection on the control chain acting on a follower, the passage of the stud or projection past such follower being arranged to take place during the occurrence of two rotations of the needle cylinder. With four steps of racking movement performed by each of two pawls and the movements of the pawls being alternate and at equal intervals it will be seen that a potential step of racking movement of the rack member will occur during each quarter rotation of the two rotations ,of the needle cylinder. The rack selecting means is arranged to be capable of selecting one or more of such racking steps to occur at a given activation of the pawl means 50 that a possibility of from one to eight increments of movement of the control drum is then caused to occur. Also in the case of less than eight such increments the rack selecting means can select any one of a suitable plurality of timings for the commencement of the racking step or steps.

In carrying out the invention the rack selecting means may be operated by the movement of the driven rack member so that at each activation of the pawl means the rack selecting means is reset to determine its selecting action at the next activation of the pawl means. This may be arranged by having included in the rack selecting means a movable member which is coupled to the driven rack member and arranged to partake of racking movements corresponding to those of the driven rack member. This movable member of the rack selecting means which in fact forms a movable selector device may take various forms, a particularly convenient one being a. short drum which is mounted on and coupled to the spindle of a rack Wheel as aforesaid which is fixed to the control drum of the machine. This selector member may conveniently have a suitable lay-out of operating projections to cooperate with a group of movable instruments for operating a blufiing device for the pawls of the pawl means, such instruments being arranged to be moved bluff activating instruments in the particular setting of the selector drum.

In practising the invention a selector drum as aforesaid may be formed in its periphery with tricks parallel to its axis at intervals corresponding to the increments of racking movement effected by the pawl means so that butt .plates can be fitted in the tricks in a required layout-having projecting butts which can be left in position or removed from the plates as required according to a patterning requirement. These butts may co-operate with sliding bars which are periodically moved endwise by cams and also caused to have rocking movement when they engage the butts, such rocking movements being used to operate a bluffing lever for bluffing a pawl. The butt plates may in some cases include an end projection adapted to engage directly with a pawl to effect bluffing action thereof.

A convenient form of racking means in accordance with the invention is illustrated by wayof example in the accompanying drawings and will now be described with reference to the drawings in which:

FIGURE 1 is a perspective view partly broken away of certain parts of racking means and rack selecting means in accordance with the invention, the lateral spread of certain of the parts being exaggerated for clearness,

FIGURES 2A-D show diagrammatically in plan view the cam actuation of certain parts of the rack selecting means in different settings,

FIGURE 3 is a face view of a butt plate used in the mechanism, and

FIGURE 4 is a perspective view of the same racking means (without exaggerated lateral spread of any of the parts) as mounted in a machine and as seen from the rear of the machine (being a different view point from that of FIG. 1), and shows further details of the racking means and an auxiliary control.

The broken view of certain of the parts of the racking means shown in FIGURE 1 illustrates at 5 a rack wheel which is fixed to the spindle of the main control drum (shown at 105 in FIG. 4) as normally provided on a circular knitting machine of the rotary needle cylinder type. With the rack wheel 5 there co-operates pawl means comprising pawls 6 and 7 which can rack the wheel 5 consecutively and are reciprocated by cam means coupled to the driving means for the cylinder so that each of the pawls 6 and 7 performs four complete strokes in each direction during each two rotations of the needle cylinder. The cam means operating the pawls 6 and 7 may be an eight lobed unitary cam block with two sections (102a, 103a, FIG. 4) one for each pawl and each having four lobes, the lobes being so timed that when one pawl advances the other retracts giving a potential of eight steps of racking movement spaced equally apart during each two cylinder rotations so that each step occurs during a quarter of a rotation of the cylinder. The operation of the pawls 6 and 7 is such that when they are permitted to engage the teeth of rack wheels 5 continuously during the two cylinder rotations the eight racking increments will succeed one another without a break .so that substantially continuous movement of the rack follower and operates a belt shipper to cause the machine to be driven at a low speed. This follower actuation also causes the pawls 6 and 7 to be unlatched for racking of the rack wheel 5 and control drum. When each pawl 6 and 7 has completed four strokes in each direction a catch is released which causes the pawls to be latched again in a forward inactive position. The belt is then shipped to cause the machine to be driven at either a medium orfast speed until the follower is again activated by a stud on the main control chain. It will be understood that by the time the four strokes of each pawl in each direction have occurred the stud on the control chain will have released the follower.

If the two pawls 6 and 7 are permitted to engage the rack wheel 5 continuously at each activation of the racking means eight increments of racking movement will be applied to the rack wheel 5 and control drum during which time two complete rotations of the needle cylinder will occur. The mechanism shown in the drawings is provided to control the four strokes of each pawl in a predetermined manner to cause each of the pawls 6 and 7 either to engage or miss the teeth of the rack wheel 5 as required. A movement of the control drum can thus be obtained in any of cylinder rotation during the two rotations of the needle cylinder and the extent to which the control drum is racked can be varied over the range of between one and eight racking increments.

As shown in FIGURE 1 a narrow drum 8 having circumferential tricks 8a forms the movable selector device of the rack selecting means and is secured to the spindle of the rack wheel 5. Inserted in appropriate ones of the tricks 8a of drum 8 there are butt plates or rack selection pieces 20 (see FIG. 3) provided with butts 9 at four positions which are broken off on individual selection pieces at places where they are not required. For a purpose later explained some of the selection pieces 20 are formed with bent over cam plates 10 at one end. The selection pieces 20 when mounted in the tricks 8a of drum 8 are retained in proper registry by means of arcuate cut-outs 21 engaged by a retaining member. The positions of the four butts 9 correspond to those of four feeler bars 1, 2, 3, 4, FIG- URES 1 and 2, having noses 1a, 2a, 3a, and 4a at their ends formed with sloped edges to enable them each to ride up on to one of the butts 9 when the feeler bars are reciprocated and a butt 9 on the path of a feeler. When this occurs the feeler bar concerned which is raised will engage with-a rod 11 projecting from a lever 12 mounted on a stub spindle 13 and raise the rod 21 and lever 12. Raising of lever 12 operates through a screw 14 and lever 15 to rock a spindle 16 which is freely mounted in a supporting bracket (not shown). Rocking of spindle 16 causes a bluff lever 17 carried by it to be raised and cause its shaped end 17a to be lifted so as to engage with pins 7a and 6b projecting from the pawls 7 and 6, and cause the pawls to be raised out of engagement with the teeth of rack wheel 5 during advancing movement of the pawls.

For the purpose of showing them more clearly the feeler bars 1, 2, 3, and 4 and other related parts are shown in FIGURE 1 as being spread widthwise of the racking means to a greater extent than occurs in practice. The feeler bars 1, 2, 3 and 4 are each mounted in a slide bracket with their tail ends urged by tension springs (not shown) respectively into contact with disc cams 22, 23, 24 and 25 in a group or such cams which are fixed to one another and to one side of the eight lobed cam which operates the two pawls 6 and 7. The disc cams and feeler bars are shown diagrammatically in FIG. 2. The feeler bars 1, 2, 3 and 4 are each, in turn, moved back a'short distance sufficient to remove each of their noses from a butt 9 should there be one positioned below the nose. The movements are shown diagrammatically in FIGURE 2, those of feeler bar 1 being for a different purpose from and described later than those of the other feeler bars. FIGURE 2A shows the feeler bar positions at the moment the pawls 6 and 7 are unlatched. Feeler bars 2, 3 and 4 are in a forward position immediately above a selection piece 20. After pawls 6 and 7 are unlatched, feeler bars 2, 3 and 4 will remain in the position shown until the needle cylinders have rotated through 180, then feeler bar 2 will move back to the position shown in FIGURE 2B. After the needle cylinders have rotated a further 180, feeler bar 3 will move back to the position shown in FIGURE 2C. When a further 180 of cylinder rotation has occurred feeler bar 4 will move back to the position shown in FIGURE 2D. This position will be maintained for nearly another 180 and then all the feeler bars 2, 3 and 4 will be returned to their original positions as in FIGURE 2A. Thus from the moment of unlatching the pawls, four periods of 180 of revolution, that is two complete revolutions of needle cylinder have been made and the pawls have made a total of eight strokes (two in each 180) whilst the feeler bars have completed their cycle.

From the above it can be seen that, if a butt 9 on selection piece 20 is positioned in the path of feeler bar 2, the pawls 6 and 7 will be held clear of the rack wheel by means of nose 2a until each pawl has made a single stroke 180 of cylinder rotation) and then feeler bar will move back off the butt and allow both pawls to engage the rack wheel. Similarly a butt engaging feeler nose 3a will maintain the pawls clear of the rack wheel also during the second stroke of their movements (during the second 180 of cylinder rotation) and then the feeler nose 3a will move back off the butt and allow both pawls to engage the rack wheel. A butt under feeler nose 4a will additionally cause the pawls to be blutfed during their third strokes (the third half revolution of the needle cylinder) and then allow engagement of the pawls with the rack wheel for their fourth stroke (i.e. racking increments '7 and 8) during the fourth half revolution which makes up the two complete revolutions of the needle cylinder which occur during the passage of one stud on the control chain. As both pawls are allowed to engage the rack wheel at the same time, the first pawl to move forward (pawl 6, FIG. 1) would always rack the drum. If this is undesirable a selection piece 20 is used which has a bent over cam plate FIG. 1 which bluffs pawl 6 directly, thus delaying racking until pawl 7 moves forward.

From the foregoing it can be seen that feeler noses 2a, 3a and 4a can operate to blutl the pawls for two, four or six strokes respectively depending upon the positioning of butts 9 to co-operate with them. By providing the bent portion 10 in addition to a butt or butts 9 on a selection piece the pawls can be blutfed for three, five and seven strokes respectively. If only a cam plate 10 is provided on a selection piece 20 the first stroke only of one pawl will be bluifed. Thus by choosing the appropriate selection piece 20 (or omitting it completely) any stroke of the pawls from one to seven may be blutfed (or none of them).

Whenever an increment of racking movement occurs the drum 8 is turned so that a fresh selection piece 20 in the next succeeding trick 8a is brought into co-operation with the feeler bars. This fresh piece 20 may not be desired to influence the feeler bars during the eight stroke sequence actually in progress. In this case the pawls must be bluffed for the remaining strokes of the sequence. The feeler bar 1 having the nose 1a is provided to fullfill this function and its movements are as follows. Peeler bar 1 remains stationary in a forward position while the pawls execute strokes two to eight. Therefore, if a butt is positioned in line with it, feeler nose 1a will bluff whatever racks remain from two to eight. Immediately after the eighth stroke of the pawls the feeler bar is moved back sufiiciently to be removed from a butt and remains in a backward position until, during the first stroke of the next cycle when it is moved forward again to be ready to prevent remaining racks in said next cycle as far as may be necessary.

Feeler bar 1 has a collapsible nose 1a (FIGURE 1) which allows the feeler bar to be moved to its forward position with the nose 1a resting in a low position up against the butt 9 from which it has been withdrawn. The nose 1a is then immediately available to be lifted by a butt 9 when the drum 8 is racked. Thus feeler bar 1 is used to prevent racking movements of the control drum by temporarily cancelling out the control by means of the other three feeler bars 2, 3 and 4. Therefore any selection piece 20 which is brought into co-operation with the feeler nose but is not required until the next chain stud is advanced under its follower, must have at least a butt 9 in line with feeler bar 1. This does not however apply if the selection piece in question is brought into co-operation with the feeler bars on the eighth (or last) rack of a sequence.

In FIG. 4 the main slide block which carries the slides to which pawls 6 and 7 are attached and also feeler bars 1, 2, 3 and 4 is indicated at 109. It is secured to a side wall 101 of the frame in a position which permits the lower ends of the feeler bars and rollers 102 and 103 of the slides 36 and 37 carrying the pawls to contact their cams 22 to 25, 102a and 103a on the main shaft 104 of the machine. The upper ends 1a, 2a, 3a and 4a of the feelers can be seen co-operating with the butts 9 of the rack selection pieces 20 carried in certain tricks of the drum 8. The pawls 6 and 7 are shown co-operating with the rack-wheel 5 and the cam drum 105 can be seen which is attached to the rack-wheel and is turned thereby, this being the main control drum of the knitting machine.

The latching means aforementioned for holding the pawls 6 and 7 in a forward inactive position comprises a control rod 106 co-operating with spring controlled latches 107 and 108 for releasing or latching the pawl slides 6a and 7a and actuated as aforementioned by studs on the main control chain of the machine.

In the event of interruption of the normal operating sequence of the machine, for example stoppage due to damage'to knitting elements or to faulty operation, it is necessary to guard against undesired racking of the rack wheel 5. Such an interruption could take place immediately after the knitting machine had commenced a new knitting sequence and before the rack wheel 5 had been caused to be racked, or it could take place after the main chain had been advanced to a position in which the racking pawls 6 and 7 had been released to commence a racking sequence but before the sequence had been completed. When correcting a fault it is usual for the machine operator to return the control chain to its start position and operate a control member to inactivate the chain racking mechanism so as to prevent further move ment of the chain, before attending to the fault. It is usual to turn the machine by hand after making the correction to ensure free running before releasing the chain racking mechanism and starting the machine on power. During such attention to the machine it would be possible for undesirable racking of the rack wheel 5 and the main control drum 105 to occur thereby throwing the sequence of control out of proper order when the machine is restarted, unless steps are taken to prevent this.

A simple means by which the above undesirable racking may be avoided is supplied by an auxiliary control coupled to the manual control just mentioned for inactivating the main chain. By this means not only is the chain racking awl blutfed but so also are the two pawls 6 and 7 for racking the rack wheel 5 and control drum 165.

Part of the manual control normally provided for inactivating the main chain as aforesaid is shown at 109 in FIG. 4. A cranked rod 109 (shown partly broken away) is turned by hand when so required to bring its cranked end 109a into contact with part of the pawl (not shown) which racks the main chain to effect disengagement of the pawl from the main chain rackwheel. The cranked end is maintained in this position by engagement in a notch in a notched plate 110. Control of disengagement of the pawls 6 and 7 from the rod 109 is efiected by a Bowden cable 111 anchored in end 109a and extending through its cover 112 to be connected at its other end to a fiat lever 113 mounted adjacent to the aforementioned lever 12 and on the same stub spindle 13. The ends of the cover 112 are anchored to fixed posts 114 and 115, The flat lever 113 has a projection (hidden in FIG. 4) which contacts the underside of lever 12 so that by pulling the cable 111 the lever 12 is lifted by this projection.

As already described, the lever 12 is normally operated (through its rod 11) by the feelers 1a, 2a, 3a and 4a which lift the lever to bluff pawls 6 and 7 through the parts 14, 15, 16 and 17. The pawls 6 and 7 will also be similarly bluifed by the auxiliary control when the cranked rod 109 is operated to inactivate the main chain. Thus by the time the machine operator has corrected the fault, turned the machine by hand and finally operated rod 109 to activate both the chain and drum racking pawls the drum pawls will have ended any sequence they may have started when the fault occurred and will be latched by parts 107 and 108 out of action, until they are again unlatched in timed relationship by a stud on the control chain.

What we claim is:

1. In a knitting machine, racking means comprising in combination a driven rack member, pawl means to engage the rack member, means mounting said pawl means for movement to rack the rack member, control means for activating said pawl means to engage and operate the rack member when required, pawl driving means to move the pawl means through a plurality of operating strokes during each period of activation by the control means, and rack selecting means operative to cause the pawl means to operate the rack member, only over a period selected from the periods corresponding to each one of and each plurality of the operative strokes of the pawl means.

2. Racking means according to claim 1 comprising blufling means to act on the pawl means to prevent the pawl means from operating the rack member during that part of its period of activation in which it is required to be ineffective.

3. Racking means according to claim 1 wherein the driven rack member is constituted by a rack wheel di rectly coupled to a control drum of the machine.

4. Racking means according to claim 1 having the pawl means constituted by a plurality of pawls operated seriatim to produce a plurality of sequential racking movements, and the rack selecting means operates to cause the pawl means to be effective only during selected racking movements.

5. Racking means according to claim 4 wherein the pawl means is provided by two pawls mounted side by side to co-operate with the rack member and the pawl driving means advances the pawls alternately and each through a plurality of operative strokes at each activation of the pawl means.

6. In a circular knitting machine of the rotary needle cylinder type, racking means comprising a driven rack member, pawl means to engage the rack member, means mounting the pawl means for to and fro movement for operation of the rack member when required, means for holding the pawl means out of engagement with the rack member, control means actuated by a stud or projection on a control chain for releasing the holding means so that the pawl means can engage the rack member, pawl driving means to drive the pawl means through a plurality of operative strokes during each period of activation by the control means, and rack selecting means operative to determine at which of the operative strokes of the pawl means it will engage and drive the rack member.

7. Racking means according to claim 6 wherein the control means releases the pawl means at each activation for a period corresponding to two rotations of the needle cylinder.

8. Racking means according to claim 7 wherein the pawl means is constituted by two pawls arranged side by side and performing operative strokes in alternation and the pawl driving means causes each pawl to have four operative racking strokes during each period of activation by the control means.

9. Racking means according to claim 8 wherein the rack selecting means'is capable of selecting any one racking step and any combination of more than one racking step during which the pawl means is effective to rack the rack member during a period of activation by the control means.

10. In a knitting machine, racking means comprising in-combination a driven rack member, pawl means to engage the rack member, control means for activating said pawl means to engage and operate the rack member when required, pawl driving means to move the pawl means through a plurality of operating strokes during each period of activation by the control means, rack selecting means capable of selecting any one racking step and any combination of racking steps more than one during which the pawl means is permitted to engage and operate the rack member, said rack selecting means being adjustable step by step, and means whereby the rack selecting means is advanced in accordance with movements of the rack member to reset it for selecting action at the next actuation of the pawl means.

11. Racking means according to claim 10 wherein the rack selecting means comprises a rotatable drum and the rack member is constituted by a rack wheel, and said drum and rack wheel are coupled to turn in unison.

12. Racking means according to claim 11 wherein the drum of the rack selection means has provision for mounting in a suitable layout on its periphery operating projections, and there is provided a group of movable instruments to co-operate respectively with operating projections at different positions on the drum and a bluffing device for the pawl means actuated by such of the said instruments as are engaged by an operating projection on the drum.

13. Racking means according to claim 12 wherein said instruments are of elongated form, and wherein there is provided "means for moving said instruments endwise to and fro in sequence tangentially of the drum of the rack selecting means whereby the instruments are caused selectively by co-operation with the projections on the drum to activate the blufiing device at predetermined times.

14. Racking means according to claim 12 wherein the drum of the rack selecting means is formed with tricks in its periphery parallel to its axis at intervals corresponding to the increments of racking movement effected by the pawl means, and wherein but-t plate are mounted in said tricks and formed with projecting butts which can be left in place or broken otf to suit a required layout of selections for the racking movements.

15. Racking means according to claim 14 wherein the rack member is constituted by a rack wheel and the drum of the rack selecting mechanism has its tricks parallel to its axis at intervals corresponding to the increments of racking movement of the rack wheel.

16. Racking means according to claim 14 wherein the movable instruments co-operate respectively with butts at different positions on the butt plates and when engaged by a projecting butt are caused to be rocked to operate the blufiing device.

17. In a knitting machine having a control chain which is racked and is provided with a manual control member by which racking of the chain may be discontinued, racking means comprising in combination a driven rack member, pawl means to engage the rack member, control means for activating said pawl means 'to engage and operate the rack member when required, pawl driving-means to move the pawl means through a plurality of operating strokes during each period of activation by the control means, rack selecting means capable of selecting any one operating stroke and any combination of operating strokes more than one of the pawl means during which the pawl means is permitted to engage and operate the rack member, and means for causing the said pawl means to be prevented from racking the rack member when racking of the control chain of the machine is discontinued by the manual control member.

18. Racking means according to claim 17 comprising blufling means for blutfing the pawl means, and an operative connection extending from the manually operated member by which discontinuance of racking of the conblutfing of the pawl means will occur whenever the racking of the control chain is discontinued.

19. Racking means according to claim 17 comprising means for holding the pawl means out of action when not required, said holding means being adapted to be released at appropriate times by a progressively moved control member of the machine so as to permit the pawl means to be actuated.

References Cited by the Examiner UNITED STATES PATENTS 2,927,447 3/1960 Mahler 66-154 3,139,742 7/1964- Lewis 66155 trol chain is effected to said blufiing means whereby 15 DONALD W. PARKER, Primary Examiner. 

1. IN A KNITTING MACHINE, RACKING MEANS COMPRISING IN COMBINATION A DRIVEN RACK MEMBER, PAWL MEANS TO ENGAGE THE RACK MEMBER, MEANS MOUNTING SAID PAWL MEANS FOR MOVEMENT TO RACK THE RACK MEMBER, CONTROL MEANS FOR ACTIVATING SAID PQWL MEANS TO ENGAGE AND OPERATE THE RACK MEMBER WHEN REQUIRED, PAWL DRIVING MEANS TO MOVE THE PAWL MEANS THROUGH A PLURALITY OF OPERATING STROKES DURING EACH PERIOD OF ACTIVATION BY THE CONTROL MEANS, AND RACK SELECTING MEANS OPERATIVE TO CAUSE THE PAWL MEANS TO OPERATE THE RACK MEMBER ONLY OVER A PERIOD SELECTED FROM THE PERIODS CORRESPONDING TO EACH ONE OF AND EACH PLURALITY OF THE OPERATIVE STROKES OF THE PAWL MEANS. 